Wiper apparatus with rise-up mechanism

Abstract

A wiper with rise-up mechanism includes a crank and a rod that is rotatably connected to the crank through a shift mechanism. The crank supports an eccentric rotor. The rod is coupled to the eccentric rotor to rotate about the axis of the eccentric rotor. A key is supported in the eccentric rotor to move axially. The key can be moved by the rotation of the crank. When the crank rotates in a normal direction, the key locks the eccentric rotor to the rod. When the crank rotates in the reverse direction, the key fixes the eccentric rotor to the crank. Only one key is used, which reduces the number of parts and simplifies the operation of the key.

What is claimed is:  
     
       1. A wiper mechanism comprising: 
       a crank, which is rotatable about a crank axis;  
       a rod for transmitting motion from the crank to a wiper arm, which supports a wiper blade, the rod having a crank end and a wiper end, the crank end being connected to the crank, wherein the axis about which the crank end of the rod pivots is a rod pivot axis;  
       a joint located between the crank and the rod, wherein the joint includes a shift mechanism for changing the axis about which the rod pivots with respect to the crank, the shift mechanism comprising:  
       a shaft supported by the crank, wherein the axis of the shaft is parallel to the crank axis;  
       an eccentric rotor, which is supported on the shaft to eccentrically rotate about the axis of the shaft, wherein the eccentric rotor has a center axis that is offset from the axis of the shaft, wherein a socket is formed on the crank end of the rod to fit on and rotate with respect to the eccentric rotor, wherein the socket includes an opening and a wall;  
       a connecting plate fixed to the crank, wherein the connecting plate includes an opening;  
       a key for selectively locking either the crank or the rod to the eccentric rotor, wherein the key is operated by the rotation of the crank, and wherein the key enters the opening of the rod to lock the eccentric rotor to the rod when the crank rotates in a first direction and the key enters the opening of the connecting plate to lock the eccentric rotor to the crank when the crank rotates in a second direction, which is opposite to the first direction, wherein the axis of rotation between the rod and the crank coincides with the axis of the shaft when the eccentric rotor is locked to the rod, and the axis of rotation between the rod and the crank coincides with the center axis of the eccentric rotor when the eccentric rotor is locked to the crank; and  
       an engaging projection formed on the eccentric rotor, wherein, when the crank rotates in one direction by a predetermined angle while the key is received in the opening of the connecting plate, the engaging projection engages the wall of the socket, which generates a force that rotates the eccentric rotor with respect to the connecting plate to move the key out of the opening of the connecting plate.  
     
     
       2. The wiper mechanism according to claim  1 , wherein the wiper blade pivots in a wiping range during continuous rotation of the crank in the first direction, wherein the crank stops at predetermined datum position after it rotates by a predetermined angle in the second direction, wherein the wiper blade is positioned in a storage position when the crank stops at the datum position. 
     
     
       3. The wiper mechanism according to claim  1 , wherein the center axis of the eccentric rotor is located between the shaft and the crank axis when the crank passes by the datum position while rotating in the first direction. 
     
     
       4. The wiper mechanism according to claim  2 , wherein the key locks the eccentric rotor to the rod when the crank first passes by a position 180 degrees from the datum position during its rotation in the first direction, and the key locks the eccentric rotor to the crank when the crank passes by a position 180 degrees from the datum position during its rotation in the second direction. 
     
     
       5. The wiper mechanism according to claim  1 , wherein the key is supported by the eccentric rotor to move axially, the key including a first end and a second end, wherein the first end can project from the eccentric rotor toward the connecting plate, and the second end can project from the eccentric rotor toward the socket. 
     
     
       6. The wiper mechanism according to claim  5 , wherein the eccentric rotor includes a through hole for supporting the key, the axial length of the key being greater than the axial length of the through hole. 
     
     
       7. The wiper mechanism according to claim  5 , wherein at least one of the first end of the key and the opening of the connecting plate includes a cam surface that serves to force the key from the opening of the connecting plate. 
     
     
       8. The wiper mechanism according to claim  5 , wherein the second end of the key is axially aligned with the opening of the socket when the engaging projection engages with the wall. 
     
     
       9. The wiper mechanism according to claim  5 , wherein the shift mechanism further includes a shutter located between the connecting plate and the eccentric rotor, wherein the shutter can rotate about the shaft with respect to the connecting plate, wherein the shutter includes an opening corresponding to the opening of the connecting plate, wherein the shutter permits the entry of the first end of the key into the opening of the connecting plate when the opening of the shutter is axially aligned with the opening of the connecting plate, and the shutter prevents the entry of the first end of the key into the opening of the connecting plate when the opening of the shutter is misaligned with the opening of the connecting plate. 
     
     
       10. The wiper mechanism according to claim  9 , wherein the shutter can rotate with respect to the connecting plate between a first limit position and a second limit position, the first limit position being angularly spaced from the second limit position by a predetermined angle, wherein the opening of the shutter is axially aligned with the opening of the connecting plate when the shutter is at the first limit position. 
     
     
       11. The wiper mechanism according to claim  10 , wherein the shutter is engaged by and moved between the first limit position and the second limit position by the first end of the key. 
     
     
       12. The wiper mechanism according to claim  10 , wherein the connecting plate includes a guide surface for guiding the first end of the key, wherein the guide surface is radially aligned with the opening of the shutter when the shutter is at the second limit position, wherein the guide surface projects in the axial direction from the connecting plate, and the shutter is closer to the eccentric rotor in the axial direction than the guide surface. 
     
     
       13. The wiper mechanism according to claim  1 , wherein a said rod is a first rod, and a second rod is connected to the eccentric rotor to rotate about the center axis of the eccentric rotor, wherein the second rod extends in a direction that is generally opposite to that of the first rod, and the eccentric rotor is located between the first and second rods, wherein the second rod converts the rotation of the crank into pivoting of another wiper arm, which supports another wiper blade. 
     
     
       14. A wiper mechanism comprising: 
       a crank, which is rotatable about a crank axis;  
       a rod for transmitting motion from the crank to a wiper arm, which supports a wiper blade, the rod having a crank end and a wiper end, the crank end being connected to the crank, wherein the axis about which the crank end of the rod pivots is a rod pivot axis;  
       a joint located between the crank and the rod, wherein the joint includes a shift mechanism for changing the axis about which the rod pivots with respect to the crank, the shift mechanism comprising:  
       a shaft supported by the crank, wherein the axis of the shaft is parallel to the crank axis;  
       an eccentric rotor, which is supported on the shaft to eccentrically rotate about the axis of the shaft, wherein the eccentric rotor has a center axis that is offset from the axis of the shaft;  
       a connecting plate, which is fixed to the crank;  
       a key for selectively locking either the crank or the rod to the eccentric rotor, the key being supported by the eccentric rotor to move in the axial direction of the eccentric rotor, wherein the key is operated by the rotation of the crank, and wherein the key enters an opening on the rod to lock the eccentric rotor to the rod when the crank rotates in a first direction and the key enters an opening in the connecting plate to lock the eccentric rotor to the crank when the crank rotates in a second direction, which is opposite to the first direction, wherein the axis of rotation between the rod and the crank coincides with the axis of the shaft when the eccentric rotor is locked to the rod, and the axis of rotation between the rod and the crank coincides with the center axis of the eccentric rotor when the eccentric rotor is locked to the crank;  
       an engaging projection formed on the eccentric rotor wherein when the crank rotates in one direction by a predetermined angle while the key is received in the opening of the connecting plate, the engaging projection engages a wall formed on the rod, which generates a force that rotates the eccentric rotor with respect to the connecting plate to move the key out of the opening of the connecting plate; and  
       a shutter, which is located between the connecting plate and the eccentric rotor, wherein the shutter can rotate about the shaft with respect to the connecting plate, the shutter including an opening corresponding to the opening of the connecting plate, wherein the shutter permits the entry of the key into the opening of the connecting plate when the opening of the shutter is axially aligned with the opening of the connecting plate, and the shutter otherwise prevents the entry of the key into the opening of the connecting plate when the opening of the shutter is misaligned with the opening of the connecting plate.  
     
     
       15. The wiper mechanism according to claim  14 , wherein the wiper blade pivots in a wiping range during continuous rotation of the crank in the first direction, wherein the crank stops at a predetermined datum position after it rotates by a predetermined angle in the second direction, wherein the wiper blade is positioned in a storage position when the crank stops at the datum position. 
     
     
       16. The wiper mechanism according to claim  14 , wherein the eccentric rotor includes a through hole for supporting the key, the axial length of the key being greater than the axial length of the through hole. 
     
     
       17. The wiper mechanism according to claim  14 , wherein at least one of the key and the opening of the connecting plate includes a cam surface that serves to force the key from the opening of the connecting plate. 
     
     
       18. The wiper mechanism according to claim  14 , wherein the key is axially aligned with the opening of the rod when the engaging projection engages with the wall. 
     
     
       19. A wiper mechanism comprising: 
       a crank, which is rotatable about a crank axis;  
       a rod for transmitting motion from the crank to a wiper arm, which supports a wiper blade, the rod having a crank end and a wiper end, the crank end being connected to the crank, wherein the axis about which the crank end of the rod pivots is a rod pivot axis;  
       a joint located between the crank and the rod, wherein the joint includes a shift mechanism for changing the axis about which the rod pivots with respect to the crank, the shift mechanism comprising:  
       a shaft supported by the crank, wherein the axis of the shaft is parallel to the crank axis;  
       an eccentric rotor supported on the shaft to eccentrically rotate about the axis of the shaft, wherein the eccentric rotor has a center axis that is offset from the axis of the shaft;  
       a connecting plate fixed to the crank;  
       a key for selectively locking either the crank or the rod to the eccentric rotor, wherein the key is operated by the rotation of the crank, and wherein the key enters an opening of the rod to lock the eccentric rotor to the rod when the crank rotates in a first direction and the key enters an opening of the connecting plate to lock the eccentric rotor to the crank when the crank rotates in a second direction, which is opposite to the first direction, wherein the axis of rotation between the rod and the crank coincides with the axis of the shaft when the eccentric rotor is locked to the rod, and the axis of rotation between the rod and the crank coincides with the center axis of the eccentric rotor when the eccentric rotor is locked to the crank; and  
       a shutter located between the connecting plate and the eccentric rotor, wherein the shutter can rotate about the shaft with respect to the connecting plate between a first limit position and a second limit position, the first limit position being angularly spaced from the second limit position by a predetermined angle, the shutter including an opening corresponding to the opening of the connecting plate, wherein, when the shutter is at the first limit position, the opening of the shutter is axially aligned with the opening of the connecting plate to permit the entry of the key into the opening of the connecting plate, and when the shutter is at a position other than the first limit position, the opening of the shutter is misaligned with the opening of the connecting plate to prevent the entry of the key into the opening of the connecting plate.  
     
     
       20. The wiper mechanism according to claim  19 , wherein the shutter is engaged by and moved between the first limit position and the second limit position by the first end of the key.